Exposing and developing apparatus

ABSTRACT

An apparatus wherein a photosensitive sheet material developable by contact with a gaseous developing agent is placed beneath an image bearing sheet material and the combination first exposed and then developed without separating the two sheet materials.

United States Patent 1 Schuman, Jr. et al.

EXPOSING AND DEVELOPING APPARATUS Inventors: Gordon A. Schuman, Jr., Rolling Meadows; Raymond W. Collins,

Schaumburg, both of III.; Yukinori Koyama, Tokyo, Japan Assignee: Dietzgen Corporation, Chicago, Ill.

Filed: Feb. 19, 1971 Appl. No.: 116,897

US. Cl. ..95/94 G, 355/106 Int. Cl. ..G03d 3/12 Field of Search ..95/89 G, 94 G; 355/106 7 References Cited UNITED STATES PATENTS 8/1937 .Kunstadter ..-..9S/94 G X LIGHT SOURCE (ANY NUMBER OF u.v. LAMPS) 1 Jan. 16,1973

2,630,744 3/1953 Wilde ..95/89 G 2,9l7,985 l2/l959 Williamson", ..355/l06 FOREIGN PATENTS OR APPLICATIONS l,062,560 3/1967 Great Britain... "95/896 1,322,930 2/1963 France ..95/94 G Primary Examiner-Samuel S. Matthews Assistant ExaminerFred L. Braun Att0rney-Jol1nston, Root, OKeeffe, Keil, Thompson & Shurtleff [57] ABSTRACT An apparatus wherein a photosensitive sheet material devclopable by contact with a gaseous developing agent is placed beneath an image bearing sheet material and the combination first exposed and then developed without separating the two sheet materials.

3 Claims, 1 Drawing Figure ORIGINAL WITH PRINTED 8 DEVELOPED COPY PERFORATED TEFLON SCREEN FOR PAPER GUIDE THRU- DEVELOPER HEATING ELEMENT DEVELOPING AREA DEVELOPING CHAMBER CHAMBER HEATING ELEMENT IIIIIII UILI IIIII- BELT TRACKING GUIDE IIIIIIII' PAPER GUIDE FROM\ DRIVE ROLLER PRINTING TO DEVELOPING AREA PAIENIEDJAIIIS I975 3.710.708

ORIGINAL WITH PRINTED a DEVELOPED COPY PERFORATED TEFLON SCREEN FOR PAPER GUIDE THRU DEVELOPER ORIGINAL SENSITIZED HEATING ELEMENT PRINT PAPE R DEVELOPING AREA LIGHT SOURCE (ANY NUMBER OF U. V. LAMPS) DEVELOPING CHAMBER CHAMBER HEATING ELEMENT "-HIIIIIII BELT TRACKING PAPER sums FROM DRIVE LLER GUIDE PRINTING TO DEVELOPING AREA INVENTORS GORDON A. S CHUMAN, JR.

RAYMOND W. COLLINS YUKINORI KOYAIVIA y z' W W W MMJM ATT'YS EXPOSING AND DEVELOPING APPARATUS BACKGROUND OF THE INVENTION dye image is formed thereon from a positive master.

Exposure to ultraviolet light under a translucent master or original such as in engineering drawing, type material, or other image-bearing design will decompose the diazo compound where it has been struck by light and retain it where it has been protected from light by opaque areas of the original. The print is then developed by reacting the retained diazo compound with a coupler to form a highly colored azo dye in precise duplication of the original.

Diazo-type reproduction processes are divided into two categories, a moist process and a dry process. The moist process is a one-component diazo-type process in which the diazo compound is on the base while the coupler is applied to the coated surface in a developer solution. The dry process is a two-component process in which both the diazo compound and the coupler are on the base and in which development is achieved without wetting by using a gaseous developing agent, viz., moist ammonia vapors to induce the coupling reaction.

ln dry processes of the type described it has been customary to separate the image-bearing sheet material from the photosensitive sheet material after exposure and before development. Such separation complicates the apparatus and very often introduces troublesome difficulties. It would be desirable, therefore, to provide a process and apparatus which is relatively simple, practically free from operating problems and inexpensive to make or use.

OBJECTS With the foregoing desiderata in mind, it is an object of the present invention to provide a new and improved apparatus and process for exposing and developing photosensitive sheet material.

Another object of the invention is to provide a new and improved apparatus and process for exposing and developing diazo-type photosensitive sheet material using ammonia vapors for development.

THE DRAWINGS Other objects and advantages of the invention will appear from the following description in conjunction with the accompanying drawing in which the single FIGURE illustrates in side elevation and with legends one form of apparatus embodying the invention.

BRIEF SUMMARY OF THE INVENTION The invention contemplates an apparatus for exposing and developing photosensitive sheet material comprising an exposing section and a developing section, said exposing section comprising a rotatable transparent cylindrical member, a plurality of circumferentially spaced parallel rollers proximate to said member, taut endless belts passing outwardly around all of said rollers and having a reversely folded section passing inwardly of said rollers, and partially encircling said member, a light source within said member adjacent said partially encircled area, means to drive one of said rollers, said sheet material being received during exposure to said light source between said belts and said member, and said developing section comprising a chamber which is enclosed except for an opening adjacent said member, a perforated blanket over said opening partially encircling said member and closely adjacent said member, means to guide said sheet material from said belts to said blanket, said sheet material after exposure being-received between the outer face of said member and the inner surface of said perforated blanket, heating means inside said member adjacent said opening, sealing means for sealing the sides of said opening while permitting ingress and egress of said sheet material to and from said developing section, means to introduce a gaseous developing agent into said chamber, means for heating said gaseous developing agent, and means to strip said sheet material from said member after said sheet material passes beyond said developing section. If the gaseous developing agent is ammonia, it can be generated in situ from aqueous ammonia or anhydrous ammonia can be used, and, if desired, water vapor can be separately added to the developing section.

The invention further contemplates a process for exposing and developing photosensitive sheet material developable by contact with a gaseous developing agent which comprises passing a light ray penetrable image bearing sheet material superimposed on a photosensitive sheet material over a rotatable transparent cylindrical member with one side of said image bearing sheet material in contact with said member and the other side in contact with one side of said photosensitive sheet material, exposing said photosensitive sheet material to light rays through said member and said image bearing sheet material while said image bearing sheet material and said photosensitive sheet material are superimposed and partially encircle a part of the circumference of said member, thereafter passing said superimposed image bearing sheet material and said photosensitive sheet material, while in contact with and partially encircling another portion of said member, through a developing zone containing a gaseous developing agent, while heating said member in an area adjacent said zone, and thereafter separating said image bearing sheet material from said photosensitive sheet material.

In practice, the photosensitive sheet material is normally made by forming a photosensitive layer on a porous base sheet material which usually consists of felted cellulose fibers, e.g., paper, but, can consist of any other type of porous sheet including plastic films or felted plastic fibers. The kind of. photosensitive composition employed in making the photosensitive layer does not form a part of the invention but the invention is primarily concerned with the use of light sensitive diazo-type materials. Examples of such materials are disclosed in U.S. Pat. No. 3,027,256, and many other examples can be given of such materials. For the primary purpose of the invention the base sheet material'on which the photosensitive layer is formed should be sufficiently porous to permit permeation of such sheet material by a gaseous developing agent such as ammonia vapors. If the base sheet'material is non-porous, the image bearing sheet material and the photosensitive sheet material can be passed through the apparatus and the process practiced as previously described except that afterthe image bearing sheet and the photosensitive sheet material have passed through the apparatus the image bearing sheet material is separated from the photosensitive sheet material and the photosensitive sheet material is reversed and is passed through the apparatus again with light source turned off so that the photosensitive layer is directly exposed to the gaseous developing agent. Inasmuch as this requires passing the photosensitive sheet material through the developing agent twice, it is less desirable, even though feasible, and in fact is still an improvement over operations in which the image bearing sheet material has to be separated from the photosensitive sheet material in the apparatus.

DETAILED DESCRIPTION OF THE INVENTION As shown 'in the drawing, the apparatus comprises a rotatable transparent cylindrical member 1 usually made of glass or any other suitable transparent material, e.g., transparent polycarbonates (Lexan). A plurality of circumferentially spaced parallel rollers 2, 3 and 4 are positioned proximate to said member 1 and a taut endless belt 5 made of rubber or any other suitable material passes outwardly around all of said rollers and has a reversely folded section passing inwardly of said rollers and partially encircling said member 1. A light source consisting of any number of ultraviolet lamps 6 isdisposed within said member 1 adjacent said partially encircled area and a reflector 7 is provided to'reflect the light rays in the direction of said-partially encircled areaLThe aforesaid partially encircled area which is generally indicated at 8 is the exposure section of the apparatus.

, The'belt 5 is driven by a motor or by any other suitable means, not shown, connected to drive roller 4.

The developing section generally indicated at 10 comprises a chamber 11 which is enclosed except for an opening 12 adjacent said member 1 and a valved inlet 13 which, as'shown, is normally in an area remote from said opening and is usually closed during operation. A perforated blanket 14 made of polytetrafluoroethylene (Teflon) or any other suitable material is disposed over opening 12 partially encircling and closely adjacent to member 1. The blanket 14 is fastened in any suitable manner at 15 to the housing 16 of chamber 11. The blanket 15 can also be fastened at point 17. A heating element 18 is disposed in member 1 adjacent the developing section. The opening 12 of the development section is sealed by blades 19 and-20 which are secured to the housing 16 adjacent opening 12 at the lower and upper ends of said opening, respectively. These sealing members 19 and 20 can be'made of spring metal which may or may not be coatedwith plastic, rubber or other material.

A developing chamber heating element 21 is provided to vaporize the developing agent in developing chamber 11. The unit is supported on base 22 and end plates, not shown. I v

The size of the'apparatus can be varied depending upon the particular need. Where large prints'are being produced, it is conventional to make the apparatus 48 inches wide in which case the member 1 would be ap-' sheet material from the exposing section to the developing section.

OPERATION In operation, the valve inlet 13 is opened in order to introduce a quantity of aqueous ammonia (or ammonia vapors) into chamber 11. The ammonia is heated by means of heating element 21 and normally a temperature of to F. is developed in chamber 11. The sensitized print paper or other photosensitive sheet material is placed beneath the original image bearing sheet material and inserted into the apparatus at 25. Thereupon it is carried between inner surface of member 26 and the outer surface of belts 5 into contact with the outer surface of member 1 where it is exposed almost immediately to raysfrom lamp 6 and continues through the exposure section 8 until it passes into the development section 10. In the development section 10 the ammonia vapors pass through the openings in perforated blanket 14 and through the porous base carrying the photosensitive layer, thereby developing the photosensitive layer. Heating element 18 should generate enough heat to prevent condensation of moisture on member l. As the image bearing sheet material and the developed photosensitive layer proceed beyond sealing blade 20 they leave the developing area and are deflected -by'a deflector 27 which is also made of spring metal or other suitable material. The image bearing sheet material is then separated by hand from the developed photosensitive sheet material. 7

If the photosensitive layer is coated on a non-porous sheet material so that the ammonia vapors cannot penetrate the base in order to completely develop the I invention isnot limited to the use of any particular type of heating element but it is usually desirable to use an electrically heated element.

From the foregoing description it will be seen that V the construction and operation of the apparatus is relatively simple. and uncomplicated. The apparatus contains no complex mechanism and is inexpensive to make. It will be understood that various types of materials can be used in constructing the apparatus without departing from the scope of the invention.

The invention is hereby claimed as follows:

1. Apparatus for exposing and developing photosen sitive sheet material comprising an exposing section and a developing section, said exposing section comprisinga rotatable transparent cylindrical member, a plurality of circumferentially spaced parallel rollers proximate to said member, taut endless belts passing outwardly around all of said rollers and having a reversely folded section passing inwardly of said rollers, and partially encircling said member, a light source within said member adjacent said partially encircled area, means to drive one of said rollers, said sheet material being received during exposure to said light source between said belts and said member, and said developing section comprising a chamber which is enclosed except for an opening adjacent said member, a perforated blanket over said opening partially encircling said member and closely adjacent said member, means to guide said sheet material from said belt to said blanket, said sheet material after exposure being received between the outer face of said member and the inner surface of said perforated blanket, heating means inside said member adjacent said opening, sealing means for sealing the sides of said opening while permitting ingress and egress of said sheet material to and from said -developing section, means to introduce a gaseous developing agent into said chamber, means for heating said gaseous developing agent, and means to strip said sheet material from said member after said sheet material passes beyond said developing section.

2. Apparatus as claimed in claim 1 in which said sheet material comprises a light ray penetrable image bearing sheet material and a porous photosensitive sheet material disposed beneath said image bearing sheet whereby rays from said light source pass through said image bearing sheet material to said photosensitive sheet material and said gaseous developing agent passes through what was initially the underside of said photosensitive sheet material, said image bearing material and said photosensitive material remaining in contact with one another throughout their passage through said exposure and developing sections.

3. Apparatus as claimed in claim 1 in which said chamber in said developing section is provided with means to introduce said developing agent in the form of liquid aqueous ammonia in an area remote from said opening, and means to heat said liquid in said remote area to generate ammonia vapors in situ[ 

2. Apparatus as claimed in claim 1 in which said sheet material comprises a light ray penetrable image bearing sheet material and a porous photosensitive sheet material disposed beneath said image bearing sheet whereby rays from said light source pass through said image bearing sheet material to said photosensitive sheet material and said gaseous developing agent passes through what was initially the underside of said photosensitive sheet material, said image bearing material and said photosensitive material remaining in contact with one another throughout their passage through said exposure and developing sections.
 3. Apparatus as claimed in claim 1 in which said chamber in said developing section is provided with means to introduce said developing agent in the form of liquid aqueous ammonia in an area remote from said opening, and means to heat said liquid in said remote area to generate ammonia vapoRs in situ. 